I’d like to say it was down to those factors, but it clearly isn’t. The vampire “scene” is still viewed as the domain of freaks, and that won’t cahnge any time soon.
IMHO I think it is merely down to screen writers providing a twist, audiences have seen “endless vampire goons turned to dust” done to death. With a film like the Blade franchise, the vampire aspect can be all but ignored, as to be honest the “vampires” could be anything, weres, drug addicts, etc. With other films however, it seems to be that if you are sticking in a character who is a “vampire”, then you best have a decent back history for them and a bloody good reason for sticking them in there. Even modern vampire villans have emotions, motives and a past. A vampire being killed simply for being a vampire and therefore evil is not good enough these days. They, like James Bond villans, must have a plan to take over the world, or kill humans, or some other way to villify them that isn’t directly tied to them being a vampire.
To me it just seems to reflect the mood of modern society towards race and the overly soft view the majority of the media has to take towards political correctness. Evil can’t be born evil, it must be a frame of mind, backed up by acts and intent. Otherwise our heros would be racism and biggoted.
But this would be merely my own opinion.